POTATO MINITUBER PRODUCTION UNDER HYDROPONIC SAND CULTURE

Abstract

Isolation and use of sterile growing media are two important factors in hydroponic
production of healthy potato mini-tubers. Sand can be disinfected by solarization,
while organic growing media may harbor some pathogenic agents. Under
hydroponic condition, number and size of potato tubers are usually controlled by
nutritional factors such as nitrogen, phosphorus and pH. The main objective of
present study was to find an appropriate combination of N, P and pH (with respect
to tuber number) under hydroponic sand culture and to evaluate some physiological
traits affected by nutrients and pH. A factorial experiment based on completely
randomized design with 4 replications was conducted. The experimental factors
included N, P and pH. Some morphological and physiological traits including tuber
number, rate of net photosynthesis, concentration of hormones ABA and IAA were
studied. Results showed that higher phosphorus concentration for 10 days
increased tuber number per plant, but tuberization was not influenced by nitrogen
interruption and intermittent reduction of pH. None of N, P and pH affected total
nitrogen concentration of potato leaf, stem and tuber. Higher phosphorus
concentration increased the level of endogenous ABA and IAA, induced
tuberization and thereby increased net photosynthesis rate of potato plants.